"For the first year since 1993, there were more daily record lows than daily highs that were either tied or set in 2013," reported Weather Channel meteorologist Guy Walton, who keeps track of the data from the climate center.

Through Dec. 28, there were 11,852 daily record lows in 2013, compared with 10,073 daily record highs, according to Walton.

A "daily" record occurs when a specific location sets a record high or low temperature for a particular day; other types of records include monthly and all-time. Walton said that an unusually cold spring was the main factor in the "cool" 2013.

The year was a stunning turnaround from the USA's amazingly warm year of 2012, when more than 34,000 record highs were measured, compared with 6,644 record lows.

Overall, the year was likely a blip in a long-term warming trend: "The ratio of daily highs to daily lows continues to be near 3 to 1 for this decade, so far," Walton said.

Also for the decade so far, there have been 700 all-time record highs set, compared with only 74 all-time record lows.

Because the USA accounts for only about 2% of Earth's surface, what happens here is far from representative of the planet as a whole.

Through November, the most recent month for which national and global climate statistics are available, the world was having its fourth-warmest year on record, while the USA was seeing its 35th-warmest on record, the National Climatic Data Center reported. Climate records go back to the 1880s.